You can make one of these yourself using PVC plumbing pipe and adhesive solvent to glue it together. Alternatively larger camping suppliers sell them around $60 to $90. This one was made by Peter & Angela Watkins. Check the space available behind your gas bottle as it does vary. With minor modifications you can use the same idea to store extra drinking water. In doubtful water areas you can keep fresh water in the front and wash up doubtful water in the A'van tank. A good system that works well.